The Importance of Protein to Support Football Performance

There are many misconceptions when it comes to protein intake for elite athletes, let alone footballers. Many still have the idea that more protein is better, with the debate of when to take on protein and what type still relatively unclear for coaches and athletes. Firstly, a practitioner must understand the needs of a player. What is their goal? Is it to increase or maintain muscle mass? Maybe the aim is to get leaner and promote fat loss. Next, a coach must analyse the situation. When are they training? What is the intensity of exercise? Here I discuss the science behind protein and how protein intake is applicable and appropriate for football athletes.

The Science

Proteins are made from 20 amino acids, some of which the body can make itself (non-essential) and some of which must be consumed in the diet (essential). The branched chain amino acids (BCAA) are three essential amino acids (leucine, isoleucine and valine) that are considered the most important when it comes to protein quality and effectiveness. These 3 BCAA’s make up 35% of muscle mass. BCAA’s are found in foods that are high in protein, with the highest concentrations found in animal proteins, including meat and dairy foods.

So what makes BCAA’s special? They have a ‘branched chain’, which makes it easier to convert each amino acid into energy during intense exercise. Only small amounts of BCAA’s are stored freely in the body. The more freely available BCAA’s there are in the body, the more they will be used for energy, which slows the breakdown of muscles cells and helps reduce muscle mass loss. This argument supports that BCAA’s can be used pre-exercise and are often added to ‘pre-workouts’ for this reason.

So what about post-exercise? Protein ingestion, in particular the BCAA leucine is well known to trigger the rate of muscle protein synthesis, which is usually supressed during exercise. Leucine acts as a ’switch’, turning on muscle protein synthesis, so ensuring that the protein source is high in leucine is essential (1).

The Theory

Protein intake guidelines have steadily increased throughout the years as more research has backed the benefits of consuming a high protein diet, especially in team sports that involve repetitive sprints, which stress the muscles. An athlete, needs to take on around 1.4 – 2g of protein per kilo of body mass per day, but this depends on the needs of an athlete, for example if they are looking to add muscle mass, more towards 2g per kilo of body mass. Any more than this and this may not show any benefit at all.

A football athlete must take on protein at regular amounts throughout the day, not just post-exercise. A source of protein should be in every meal of the day, including between meals. Although meal preparation is an ideal method to hit protein goals, it’s not always practical, especially when the aim is to take in 20-25g of protein every 3-4 hours. Some nutrition companies offer a range of convenient protein snacks and bars, but consider what that snack would be like with the protein taken away, would it just be a chocolate bar? I implement Science in Sport (SiS) WHEY20’s into a footballers diet as a ‘between meal’ snack. They contain 20g of whey protein hydrolysate (not collagen- a low quality fish protein that is in the majority of other ‘protein gels’), in an innovative, yoghurt like format that doesn’t need to be refrigerated. This is where supplements can be appropriate. Interestingly, a study by Moore and colleagues (2) found that there was no benefit of consuming more that 20g of protein at any one time, highlighting the importance to spread protein intake throughout the day.

Data from: Moore et al. (2009)

Fast digesting proteins such as whey protein concentrate and isolate is ideal to take post-training or game, when the body will absorb nutrients more effectively. Soy protein is a vegan/vegetarian alternative to whey protein, although it is not digested as rapidly. These proteins are not limited for use post-exercise, they can also be used between meals to help contribute to an individual’s protein intake goal.

A milk-based protein digests more slowly and is ideal to take pre- sleep, to continuously feed muscles with protein overnight. After all, it’s during sleep when adaptations take place. Milk protein is made of 80% casein (slow digesting) and 20% whey protein (fast digesting) making it ideal to take on the night of a high intensity training session or match. Since it’s not practical to wake up in the night and take on protein to help maintain muscle protein synthesis, milk protein can help provide a continuous supply of amino acids to the muscles. The graph below (3) shows the difference of digestion between whey, soy and casein. Whey and soy are shown to digest more rapidly, providing amino acids to the muscle faster, while casein provides a steady stream of amino acids.

Data from: Tan et al. (2005)

The Application

Firstly, let’s look at the benefits of getting protein intake right. Essentially when protein intake is supported with a specific exercise regime, a player can look to either build muscle, maintain the muscle they already have and/or reduce the negative impact that football has on the muscles (e.g muscle breakdown).

As a performance nutritionist, I would recommend that a football player, participating in football at least 2-3 times per week should try to consume 20-25g of protein every 3-4 hours from a range of protein sources. This aim here is to constantly trigger muscle protein synthesis and prevent muscle breakdown. Think of muscle fibres as having tiny workmen, every time an athlete exercises, workmen repair the muscle fibres that have been damaged. If you don’t fuel the workmen with protein (and other essential nutrients) they won’t repair the damage!

Summary protein intake considerations for a football player:

20-25g of protein every 3-4 hours is needed to maintain muscle protein synthesis

4 – 2g of protein per kilo of body mass per day, when training/ competing at a high intensity

Immediately post exercise, consume 0.3 grams of protein per kilo of body mass immediately post exercise (within 30 minutes), this is when the muscle is most responsive to the intake of nutrients.

Remember- additional protein can’t be stored by the body and will eventually be excreted

Food comes first, an athlete doesn’t always need a protein shake, however shakes can provide exactly what an athlete needs, when they need it

When looking to supplement with protein, use whey protein (or soy) throughout the day and/or a casein based protein supplement before sleep

Ted is currently in his second season providing sports science support Hull City Football Club. He graduated with first class honours in (BSc) Sport Coaching and Performance and is currently undertaking a part time MSc in Sport Science & Physiology. For numerous years Ted trained as a tennis athlete, competing in regional and national competitions which provided him with the opportunity to grow up working and playing with some top British talent. He continues to work with young players as Strength and conditioning coach, while providing individual nutrition strategies. This, along with placements at Hull FC helped enable Ted to become a Sports Science Intern at Hull City, where he continues to provide S&C and nutritional advice, while monitoring GPS training load.